Effectiveness analyses may underestimate protection of infants after group C meningococcal immunization
Background. Group C meningococcal conjugate-vaccine effectiveness in the United Kingdom declines from ~90% in the first year to 0% between 1 and 4 years after immunization in infants immunized at 2, 3, and 4 months of age and to 61% in toddlers given a single dose. Confidence intervals are wide, and...
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| Format: | Journal article |
| Language: | English |
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University of Chicago Press
2006
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| author | Vu, D Kelly, D Heath, P McCarthy, N Pollard, A Granoff, D |
| author2 | Infectious Diseases Society of America |
| author_facet | Infectious Diseases Society of America Vu, D Kelly, D Heath, P McCarthy, N Pollard, A Granoff, D |
| author_sort | Vu, D |
| collection | OXFORD |
| description | Background. Group C meningococcal conjugate-vaccine effectiveness in the United Kingdom declines from ~90% in the first year to 0% between 1 and 4 years after immunization in infants immunized at 2, 3, and 4 months of age and to 61% in toddlers given a single dose. Confidence intervals are wide, and the extent of protection is uncertain. Methods. Serum samples were obtained from children 3-5 years of age who were participants in a preschool booster-vaccine trial. Serum bacterial activity was measured with human complement. Group C anticapsular antibody concentrations were measured by a radioantigen binding assay. Passive protection was analyzed in a infant rat bacteremia model. Results. Serum samples from UK children who had been immunized 2-3 years earlier as infants or toddlers had higher levels of radioantigen binding, bacterial activity, and passive protection than did historical control serum samples from unimmunized children (P<.05). A higher proportion of children immunized as infants had serum bactericidal activity tiers ≥ 1:4 (considered to be protective) than those immunized as toddlers (61% vs. 24%; P<.01), but there were no significant differences in the proportion of serum samples conferring passive protection (50% and 41%, respectively; P=.4). Conclusions. We found no evidence of lower immunity in children immunized as infants than as toddlers. On the basis of serum bactericidal activity and/or passive protection, 40%-50% of both age groups are protected at 2-3 years after immunization, which was significantly greater than in unimmunized historical controls (<5%). |
| first_indexed | 2024-03-07T00:46:06Z |
| format | Journal article |
| id | oxford-uuid:84b67169-71c5-48a5-8cef-c772c4c2fe96 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T00:46:06Z |
| publishDate | 2006 |
| publisher | University of Chicago Press |
| record_format | dspace |
| spelling | oxford-uuid:84b67169-71c5-48a5-8cef-c772c4c2fe962022-03-26T21:52:55ZEffectiveness analyses may underestimate protection of infants after group C meningococcal immunizationJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:84b67169-71c5-48a5-8cef-c772c4c2fe96VaccinologyZoological sciencesPaediatricsEnglishOxford University Research Archive - ValetUniversity of Chicago Press2006Vu, DKelly, DHeath, PMcCarthy, NPollard, AGranoff, DInfectious Diseases Society of AmericaBackground. Group C meningococcal conjugate-vaccine effectiveness in the United Kingdom declines from ~90% in the first year to 0% between 1 and 4 years after immunization in infants immunized at 2, 3, and 4 months of age and to 61% in toddlers given a single dose. Confidence intervals are wide, and the extent of protection is uncertain. Methods. Serum samples were obtained from children 3-5 years of age who were participants in a preschool booster-vaccine trial. Serum bacterial activity was measured with human complement. Group C anticapsular antibody concentrations were measured by a radioantigen binding assay. Passive protection was analyzed in a infant rat bacteremia model. Results. Serum samples from UK children who had been immunized 2-3 years earlier as infants or toddlers had higher levels of radioantigen binding, bacterial activity, and passive protection than did historical control serum samples from unimmunized children (P<.05). A higher proportion of children immunized as infants had serum bactericidal activity tiers ≥ 1:4 (considered to be protective) than those immunized as toddlers (61% vs. 24%; P<.01), but there were no significant differences in the proportion of serum samples conferring passive protection (50% and 41%, respectively; P=.4). Conclusions. We found no evidence of lower immunity in children immunized as infants than as toddlers. On the basis of serum bactericidal activity and/or passive protection, 40%-50% of both age groups are protected at 2-3 years after immunization, which was significantly greater than in unimmunized historical controls (<5%). |
| spellingShingle | Vaccinology Zoological sciences Paediatrics Vu, D Kelly, D Heath, P McCarthy, N Pollard, A Granoff, D Effectiveness analyses may underestimate protection of infants after group C meningococcal immunization |
| title | Effectiveness analyses may underestimate protection of infants after group C meningococcal immunization |
| title_full | Effectiveness analyses may underestimate protection of infants after group C meningococcal immunization |
| title_fullStr | Effectiveness analyses may underestimate protection of infants after group C meningococcal immunization |
| title_full_unstemmed | Effectiveness analyses may underestimate protection of infants after group C meningococcal immunization |
| title_short | Effectiveness analyses may underestimate protection of infants after group C meningococcal immunization |
| title_sort | effectiveness analyses may underestimate protection of infants after group c meningococcal immunization |
| topic | Vaccinology Zoological sciences Paediatrics |
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